1. Field of the Invention
The present invention relates to an image data sorting device and a method of the same that sort image data pieces, especially, digital data pieces of static color images.
2. Description of the Related Art
Many database servers and file servers having a function to store image data pieces achieve efficiency in the management and retrieval of the image data pieces, etc., by sorting the image data pieces into several groups.
In the conventional major method of sorting image data pieces, cord information such as a key word is added to each of the image data pieces. This is because the addition of cord information exceedingly facilitates the management and the retrieval of the image data pieces by using the cord information as the key. However, in the addition of the cord information to the image data pieces, grouping and storing the image data pieces, or retrieving and fetching the image data pieces requires inputting the cord information through a keyboard or the like that necessarily accompanies considerable labor, which is a disadvantage.
From this view, several methods of sorting image data pieces without needing the addition of the cord information have been proposed in recent years. For example, Japanese Published Unexamined Patent Application No. Hei 7-160844 has disclosed a filing device that sorts image data pieces by judging a similarity between the image data pieces on the basis of characteristic values of the image data pieces. Such a filing device calculates the characteristic values of the image data pieces newly inputted, reads the characteristic values of the image data pieces that have already been stored and grouped, calculates the similarities between the calculated characteristic values and the characteristic values read out to acquire the maximum value thereof, and judges that the inputted image data pieces belong to the group that gives the maximum similarity.
Also, Japanese Published Unexamined Patent Application No. Hei 10-198683 has disclosed a sorting method that executes character recognition processing to image data pieces and sorts the image data by judging a similarity between the image data pieces. Such a sorting method executes the character recognition processing to image data pieces newly inputted, calculates the similarities on the basis of the characteristics of character types by the recognition processing and the total number of the characters to acquire the maximum value thereof, and judges that the inputted image data pieces belong to the group that gives the maximum similarity. Further, among each of the groups, the method selects a representative image data piece that best illustrates the characteristics of the group.
However, there is a possibility of causing the following problems in the conventional image data sorting methods mentioned above. In case of the filing device disclosed in Japanese Published Unexamined Patent Application No. Hei 7-160844, since sorting is executed based on whether or not the image data pieces belong to the sorting (grouping) items that have already existed, if the range of the sorting items that have already existed is not appropriate, preferable sorting will not be executed, leading to a possible result that sorting of the image data pieces is inappropriate.
In contrast to this, the sorting method disclosed in Japanese Published Unexamined Patent Application No. Hei 10-198683 sets the representative image data piece that best illustrate the characteristics of the sorting items each and registers these in advance, thereby enhancing the appropriateness of the sorting items. However, this sorting method executes sorting on the basis of the characteristics of character types processed by the character recognition processing, etc., and the method cannot sort natural image data pieces and the like where characters do not exist, accordingly.
Further, in any case of the above two (the filing device of Japanese Published Unexamined Patent Application No. Hei 7-160844, and the sorting method of Japanese Published Unexamined Patent Application No. Hei 10-198683), in order to secure the appropriateness of the range of the sorting items, the following will become indispensable: the preparatory processing such as setting the representative image data pieces that best illustrate the characteristics of the sorting items and the like, and the maintenance work such as dividing the item, etc., in case of the number of registering to a certain sorting item becoming too large.